Method and apparatus for determination of hole burning susceptibility of materials



N v- 30, 1965 K. R. OLIVER, JR.. ETAL 3,220,242

METHOD AND APPARATUS FOR DETERMINATION OF HOLE Filed Jan. 8, 1962BURNING SUSCEPTIBILITY OF MATERIALS 2 Sheets-Sheet 1 INVENTORS 0 KENNETHOLIVER, L/R.

mvo NED D. WAG/V R Nov. 30, 1965 K. R OLIVER, JR. ETAL 3,220,242

METHOD AND APPARATUS FOR DETERMINATION OF HOLE BURNING SUSCEPTIBILITY OFMATERIALS Filed Jan. 8, 1962 2 Sheets-Sheet 2 INVENTORS KENNETH R.OL/VER, JR MD A/ED 0. WAGNER United States Patent 3,220,242 METHOD ANDAPPARATUS FOR DETERMINA- TION 0F HOLE BURNING SUSCEPTIBILITY OFMATERIALS Kenneth R. Oliver, Jr., 10403 Warwick Blvd, Newport News, Va.,and Ned D. Wagner, 44 Whittaker Ave., Hampton, Va.

Filed Jan. 8, 1962, Ser. No. 164,739 7 Claims. (Cl. 73-15) Thisinvention relates to a method and apparatus for determination of holeburning susceptibility of materials, more particularly fabrics.

Various methods and apparatus have been proposed and utilized formeasuring the relative susceptibility of fabrics to hole melting or holeburning, which methods and apparatus have generally been quitecumbersome in use. Such methods are often based upon a direct analogy tohole melting from cigarette embers, and consist of determination of thetemperature to which objects of standard size must be heated, so whenbrought in contact with the fabric under test, they will burn a hole, orotherwise fuse through the fabric.

Testing by using cigarettes is too inconclusive. The large variationsbetween brands due to type of tobacco, packing, moisture content, etc.,prevent repeatability of results. Such variations cause differenttemperature and rates of burning.

The inventive concept of the present invention is characterized by amethod and apparatus which features simplicity in use and repeatabilityof results. The apparatus of the invention provides reliable evaluationof the susceptibility of hole melting, or hole burning, of fabrics.

Briefly, the subject apparatus comprises a stylus which is heated to agiven temperature and applied in a spiral path to a piece of fabric. Asthe relative speed between the stylus and fabric increases in onedirection of movement, a burn, or scorch pattern will be developed whichvaries in intensity, or degree, relative to the speed of the stylus uponthe fabric. Comparison of test results between a given fabric, against agiven standard for such type fabric, will provide a good indication ofthe susceptibility of the tested fabric to hole burning, or scorching.

The main object of this invention is to provide a method and apparatusfor determination of hole burning susceptibility of fabrics.

A more specific object is to provide a fabric hole burning tester whichis characterized by simplicity in use and repeatability of results.

Still another object is to provide a fabric hole burning tester whichaffords reliable evaluation of the susceptibility of hole melting, orburning, of various fabrics.

These and further objects and features of the invention will become moreapparent from the following description and accompanying drawingswherein:

FIG. 1 is an elevation view, in partial section, of apparatusillustrative of an embodiment of the invention;

FIG. 2 is a plan view of the same;

FIGS. 3 and 4 are illustrations of burn patterns made in sample materialwhen using the apparatus of FIG. 1; and

FIGS. 5 and 6 are illustrations of burn patterns made by cigarettes uponsample materials.

Referring now to the drawings and more particularly to FIGS. 1 and 2,numeral 10 identifies apparatus embodying the principles of theinvention, which includes a sample mounting turntable, or disc 12,supported for rotation in a base means 14, and a stylus assemblage 16,which is also supported for rotation in the base means.

The sample mounting table 12 is preferably formed of a metal, such asaluminum, and is covered with a thin 3,220,242 Patented Nov. 30, 1965sheet 18 of asbestos to retard heat dissipation by other than thesample. An edge groove 20 is formed in the disc for receipt of a rubberring 22 which holds a sample 24 in taut position upon the top of theturntable during a test run. A gear 26 is afiixed to a shaft 28 uponwhich the disc 12 is mounted, which gear is adapted for meshing with agear 30 driven by a motor 32 positioned in the base means 14. A bushing34 may be arranged in the base means for the rotary support of the shaft28, while a bushing 36 may be likewise arranged for the support of ashaft 38 forming part of the stylus assemblage 16.

A gear 40 is affixed to a rod, or shaft member 42 of the stylusassemblage 16, which gear is adapted for meshing with a gear 44 drivenby a motor 46 positioned in the base means 14. Motor 32 is preferablyoperated at one rev. min. while motor 46 is operated at one rev./ hr.

The stylus assemblage 16 includes a horizontally disposed arm member 48,one end of which is afiixed to the upper extremity of the shaft 42,while the other end has a clamping arrangement 50 for the support of anelectrically heated element, or stylus 52. The latter may be formed of athree turn coil of 0.120" diameter No. 26 chromel wire, immersed in arefractory material such as Sauereison, a synthetic porcelain cementmade by the Sauereison Cement Company, said coated wire being encased ina quartz tube, having a spherical tip for engagement with a sample 24under test. The heatingof the stylus 52 is regulated by an 8 amperevariable autotransformer (not shown), which is set with a calibrationthermocouple. Tip temperatures of the stylus may be adjusted'to conformwith standards established by experimentation; in tests made byapplicants, a temperature range of 500 F. to 850 F. was used.

The operation of the test apparatus 10 is very simple. A sample ofmaterial is placed upon the turntable as shown in FIG. 1. The stylusassemblage 16 is positioned upon the base means 14 so that the stylus 52will be moved in an arcuate path to create a spiral inwardly directedpath upon the material, such as the path taken by a phonograph pickup ona phonograph record. The degree of contact of the stylus is unimportantfor, obviously, the heat of the stylus may be such that burning iseffected. A standardized contact pressure of the stylus upon thematerial under test of 6.5 grams was used by applicants.

FIG. 3 illustrates the results of a test run on a piece of 100% woolfabric, with a stylus temperature of ap proximately 840 F., and aturntable speed of one rev./ min. FIG. 4 illustrates the results of atest run on a piece of Orlon (tradename of material made by the du Pontde nemours Company) fabric, under the same conditions as that used onthe FIG. 3 sample. In FIG. 5 a sample is shown having burn patterns madeupon 100% wool fabric after two minute exposures to a lighted cigarette,while in FIG. 6 cigarette burn patterns are shown as made upon Orlonafter two minute exposures. The similarity between the type of fabricburn resistance of FIGS. 3 and 4, and FIGS. 5 and 6 respectively, willbe apparent.

It will be noted that as the relative speed between the stylus tip andthe sample material decreases as the stylus moves toward the center ofthe sample, the burn effects become progressively more pronounced. Itwill also be noted that the susceptibility to hole burning or scorchingof wool is lower than that of the Orlon.

In such manner, comparative tests may be made between different samplefabrics made from the same type of materialsuch tests being useful inquality control operationsas well as between sample fabrics of differentmaterials-for purposes of fabric evaluation, or selection.

From the foregoing it will be apparent that the method and apparatus asabove described will satisfy all of the objectives hereinbefore setforth.

The foregoing description has been given in detail without thoughtoflimitation since the inventive principles involved are capable ofassuming other forms Without departing from the spirit of the inventionor the scope of the following claims.

What is claimed is:

1. A method for determination of hole burning susceptibility of a fabriccomprising, heating a stylus so that it attains a predetermined tiptemperature, arranging a piece of fabric in a given plane, rotating thefabric at a constant rate While the stylus tip is in contact with thefabric, and moving the stylus at a constant rate of speed toward thecenter of rotation of the fabric to form a spiral burn pattern upon thefabric.

2. Apparatus for determination of hole burning susceptibility of afabric comprising in combination, a turntable arranged for mounting of afabric thereupon, a stylus having a tip heated to a predeterminedtemperature, means for rotating the turntable at a given speed, andmeans for moving the stylus tip in an arcuate pattern across the fabric.

3. Apparatus for determination of hole burning susceptibility of afabric comprising in combination, a turntable arranged for mounting of afabric thereupon, a stylus having a tip heated to a predeterminedtemperature, means for rotating the turntable at a given speed, andmeans for moving the stylus tip in an arcuate pattern at a given speedacross the fabric.

4. Apparatus for determination of hole burning susceptibility of afabric comprising in combination, a turntable arranged for mounting of afabric thereupon, a stylus having a tip heated to a predeterminedtemperature, motor means for rotating the turntable at a constant speed,support means for holding the stylus in contact with the fabric, andmotor means for moving the stylus tip in an arcuate pattern at aconstant speed across the fabric.

5. A method for determination of hole burning susceptibility of amaterial comprising, heating an element to a predetermined temperature,placing the element in contact with the material to be tested, andmoving the element and the material relative to one another at avariable rate of speed with the element being moved in a plane parallelwith the material to develop a burn pattern on the material.

6. A method for determination of hole burning susceptibility of amaterial comprising, heating a stylus to a predetermined temperature,placing the stylus in contact with the material to be tested, moving thestylus and the material relative to one another at a variable rate ofspeed in an arcuate path to generate a spiral burn pattern on thematerial.

7. Apparatus for determination of hole burning susceptibility of afabric comprising in combination: a turntable arranged for mounting afabric thereon, a stylus having a tip heated to a temperature capable ofburning said fabric, and support means capable of moving said stylus andsaid turntable relative to one another at a variable rate of speed withsaid stylus being in a plane parallel With said turntable.

References Cited, by the Examiner UNITED STATES PATENTS 1,664,221 3/1928Matthews et al. 7315 2,547,367 4/1951 Booth 7315 2,895,327 7/1959 Monegoet a1. 73-15 2,958,366 11/1960 Conti 73-15 X 3,088,309 5/1963 White,Jr., et al. 7315 FOREIGN PATENTS 80,275 3/ 1920 Austria.

RICHARD C. QUEISSER, Primary Examiner.

ROBERT L. EVANS, DAVID SCHONBERG, Examiners.

2. APPARATUS FOR DETERMINATION OF HOLE BURNING SUSCEPTIBILITY OF AFABRIC COMPRISING IN COMBINATION, A TURNTABLE ARRANGED FOR MOUNTING OF AFABRIC THEREUPON, A STYLUS HAVING A TIP HEATED TO A PREDETERMINEDTEMPERATURE, MEANS FOR ROTATING THE TURNTABLE AT A GIVEN SPEED, ANDMEANS FOR MOVING THE STYLUS TIP IN AN ARCUATE PATTERN ACROSS THE FABRIC.